Encased motor compressor

ABSTRACT

THE INVENTION RELATES TO A LUBRICATING SYSTEM FOR A MOTORCOMPRESSOR ASSEMBLY OF THE TYPE USED FOR SMALL REFRIGERATING MACHINES. THE ASSEMBLY HAS A VERTICAL SHAFT ARRANGEMENT WITH A CENTRIFUGING DISC ATTACHED TO THE TOP OF THE SHAFT FOR FLINGING LUBRICATING OIL TO THE INTERNAL WALL OF THE CASING BY CENTRIFUGAL FORCE. THE SHAFT HAS SHOULDER OR FLANGE WHICH FORMS A PART OF AN AXIAL THRUST BEARING ARRANGEMENT AND THE CENTRIFUGING DISC HAS OUTWARDLY INCLINED WALL MEANS WHICH EXTENDS FROM A LEVEL BELOW TO A LEVEL ABOVE THE SHOULDER OF THE SHAFT.

United States Patent f 72] inventors liens Ulrik Letters; [56]References Cited Bend! Wegge o Sonderborg, v UNITED STATES PATENTSDenmark 2,072,307 3/1937 Kenney 230/207X 2%; 321 1969 2,228,364 1/1941Philipp 230/58 1 9 [45] Patented June 28, 1971 Primary Examiner-RobertM. Walker 7 Assignee Danfm Att0rneyWayne B. Easton Nordborg, Denmark[32] Priority June 19, 1968 2 2 ABSTRACT: The invention relates to alubricatin s stem for g y 1 ,wP4 Z.. .1 a motor-compressor assembly ofthe type used for small refrigerating machines The assembly has avertical shaft arrangement with a centrifuging disc attached to the topof the [54] S y u COMPRESSOR shaft for flinging lubricating oil to theinternal wall of the easscl rawmgfigs ing by centrifugal force. Theshaft has a shoulder or flange 52 US. Cl 184/6.16 which forms a part ofan axial thrust bearin arran ement and g g [5 1] Int. Cl F0lm 1/00 thecentrifuging disc has outwardly inclined wall means which [50] Field ofSearch 230/206, extends from a level below to a level above the shoulderof the 207, 58, l39;4l7/372; 184/6 shaft.

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1 4/ I 1 A l g 55E PATENTEDJunzs :97:

SHEET 2 OF 2 Fla 2 ENCASED MOTOR COMPRESSOR I The invention relates toan encased motor-compressor, particularly for small refrigeratingmachines and comprising a vertical shaft arrangement having an axialbearing and at least one oil-outlet orifice at the upper end-face, fromwhich orifice the oil is flung on to the wall of the case by centrifugalforce.

This oil runs along the wall of the case back into the sump and iscooled in so doing. In order to keep the temperature of the oil as lowas possible, it is desirable to pass the greatest quantity of oil overthe wall of the case. Only a limited quantity of oil is available forthis purpose, however, i.e. the difference between the supply capacityof the oil pump and the quantity of oil required for lubricatingpurposes.

These conditions apply for example in the case of a known motorcompressor having a vertical shaft arrangement and a cylinder positionedat the top, the axial bearing being located below the crank and aninclined bore extending through the crank in such manner that the mouthof the outlet is disposed outside the axis of rotation of the shaft.

It is also known to employ centrifuging discs in motor compressors fordistributing the oil.

The object of the invention is to provide a motor compressor of theinitially described kind and of simple construction, in which thequantity of oil cooled on the wall of the case can be increased.

According to the invention this is done by the shaft arrangement havinga shoulder to form the axial bearing at its upper end and carrying acentrifuging disc with an upwardly inclined edge, which extends from alevel below the shoulder to a level above the end-face.

In this arrangement, the axial bearing is upwardly extended to such anextent that the lubricating oil emerging therefrom can be caught by thedownwardly extending edge of the centrifuging disc. Consequently, thecentrifuging disc not only distributes the oil emerging from the orificeat the end-face, but also distributes, on the wall of the casing, theoil passed to the axial bearing for lubricating purposes. A moreintensive cooling effect is consequently obtained.

It is not necessary for the edge of the centrifuging disc to extend overthe entire circumference. If the oil-outlet orifices are only on oneside of the end-face, it suffices if the edge of the centrifuging discextends only over a portion of the circumference extending on this side.

In a further aspect of the invention, an oil-fed lubricating groove isprovided in the shoulder and extends towards the edge extending over thecircumferential portion. This lubricating groove imparts a preferentialdirection to the oil supplied to the axial bearing, so that, in themain, it impinges on the circumferential portion of the edge of thecentrifuging disc that is present.

A particularly simple construction is obtained if the shoulder is formedby the underside of a disc which is secured to the end-face of the shaftand which contains an opening for the outlet of oil and a lubricatinggroove running therefrom on the underside.

In a preferred embodiment, that portion of the circumference notoccupied by the edge of the centrifuging disc is occupied by acompensating weight connected to the shaft. This results in goodutilization of space. Furthermore, the particular portion of thecircumference opposite the crank can be unoccupied by the edge of thecentrifuging disc if axially parallel oil passages extend through theshaft and the crank.

Additionally, the axial bearing can be arranged within a recess in thehousing of the compressor and the upper rim of the edge of thecentrifuging disc can project from the recess. Although a constructionthat is very short in axial direction can be obtained by thisarrangement, the oil flung out from the axial bearing into the recesscan be carried to the wall of the case with the help of the edgeof thecentrifuging disc.

An embodiment of the invention will now be described in greater detailby reference to the drawing, in which:

FIG. 1 shows a longitudinal section through the motor-compressor of theinvention,

FIG. 2 is a central partial section through the upper end of themotor-compressor in a plane at right-angles to that of F lG.

FIG. 3 is a view from below of the centrifuging disc employed,

FIG. 4 is a view from below of the axial bearing disc used, and

FIG. 5 is a section through the motor crankshaft, on the line A-A ofFIG. 1.

The motor compressor is mounted, on springs (not illustrated), in acase 1. In the lower part of the case is an oil sump 2. An oil-supplypipe 3, the lower end of which is formed as a hollow cone 4, extendsinto this sump. The supply pipe 3 is pressed in the bore 5 ofa motorshaft 6, which drives a compressor piston (not illustrated) through acrank 7, a crank bearing 8 and a connecting rod 9. The shaft is held ina first radial bearing l0, which is formed in the carrier member 11 forthe motor, and in a second radial bearing 12, which is formed in aninsert 13 contained in the carrier member 11. An axial bearing is formedby the underside 14 of a disc 15, secured to the end-face of the shaft6, in conjunction with the upper end-face of the radial bearing bush 12.Above this is located a centrifuging disc 16. The two discs 15 and 16are detachably secured to the shaft 6 by means of a screwbolt l7 and areheld against rotation with the help of a pin 18. The motor consists of astator 19, connected to the carrier member 11, and a rotor 20, connectedto the shaft. The upwardly extending wall 21 of the carrier member 11,together with the insert 13, forms noise-reducing chambers 22.

The oil delivered by the pipe 3 rises in the bore 5 of the shaft 6; partof it is deflected through a bore 23 for lubricating the radial bearing10. The rest continues upwards through three axially parallel bores 24,25 and 26, the position of which can be seen from FIG. 5. Oil isdeflected through a transverse bore 27 for lubricating the crank bearing8. The oil emerging from the three bores 24, 25 and 26 passes into anopening 28 in the disc 15. From there the oil can be distributed,through a radially extending groove 29, over the surface of the axialbearing on the underside 14 of the disc. The remaining oil passesthrough a cutaway portion 30 in the edge of the centrifuging disc toreach the edge 31 thereof, and is thence flung on to the wall ofthe caseby the rim 32.

As FIG. 3 shows, the centrifuging disc 16 has, only over somewhat lessthan half ofits periphery, an upwardly inclined edge 31, this edge infact being on the same side as that where the three bores 24, 25 and 26run out from the end-face of the shaft 6. The lower rim 33 of the edge31 is located below the underside 14 of the disc 15. The rim 32 is abovethe end-face of the shaft arrangement, i.e. above the cutaway portion 30in the centrifuging disc 16 and is also above the upper end-face of thecarrier member 11. Consequently the oil emerging in the zone of theaxial bearing is also caught, although this point is located below theend-face of the carrier member, and the oil is passed to the wall of thecasing.

On the side opposite the crank 7, the disc 15 is provided with anadditional part ring 34 to which is also fitted, by means of rivets 36,a further ring portion 35. For the sake of clarity, one of the rivets 36is shown in section in FIG. 2. ln this way, there is created acompensating weight whereby the out-ofbalance caused by the crank 7 canbe compensated. Around the upper radial bearing bush 12 is an annularchamber 37, in which is set back a part 38 of the end-face of the insert13. Not only can the one illustrated further ring portion 35 beaccommodated in this annular chamber, but, if required, a second one. Itwill be clearly seen that these ring portions are positioned preciselyopposite the centrifuging disc, so that the two parts cannot collidewith each other.

For the purpose of achieving further weight-compensation, the uppershort-circuiting ring 39 of the rotor 20 has an enlargement 40 over thathalf of its circumference on the side opposite the crank. In this way acompensating weight is provided above and below the crank 7, so that thearrangement is subject to extremely little imbalance.

The disc can be fitted after the motor compressor has been assembled.There is no difflculty in obtaining optimum balancing by introducingadditional weights or by substituting another disc.

We claim:

1. A motor-compressor assembly comprising a casing, a carrier framedisposed internally of said casing, said frame defining a radial bearingand an upper axial bearing, a shaft rotatably joumaled in said radialbearing and having flange means engaging said axial bearing, and acentrifuging disc attached to said flange means having outwardlyinclined-wall means. extending above and below said flange means, saidshaft having vertically extending oil passages with upper oriflcesopening on only one diametric side thereof, said centrifuging disc wallmeans being only on said diametric side of said shaft.

2. A motor-compressor assembly according to claim 1 wherein said flangemeans has an opening on said diametric side of said shaft in surroundingrelation to said orifices, and a groove in the lower side of said flangemeans extending in a radially outwardly direction from said opening forlubricating said axial bearing.

3. A motor-compressor assembly according to claim 2 wherein said flangemeans is a separate disc member attached to said shaft. I

4. A motor-compressor assembly according to claim 2 includingcounterweight means attached to said flange means on the diametric sidethereof opposite said one diametric side.

5. A motor-compressor assembly according to claim 1 wherein said carrierframe definesan annularly shaped recess surrounding said axial bearing,said centrifuging disc wall means having a lower portion thereof withinthe confines of said recess.

